Influence and Suppression of Large Capacity Impact Load on Power Quality of Power System

With the rapid development of industry, large capacity impact load, such as high-power water pump with soft start, industrial arc furnace and so on, causes active and reactive power impact and a large number of harmonic injection in the production and operation process, which has a serious impact on the power quality of the distribution network. Based on PSAF software, a simulation model of an impact load connected to the distribution network is established, and the bus bar connected to the common point is affected. The paper analyzes and evaluates the harmonic, voltage imbalance and voltage fluctuation of the bus bar, and expounds the influence of large capacity fluctuating load such as electric arc furnace on the power quality of distribution network. The analysis results show that the large capacity impact load easily causes the power quality index of distribution network to exceed the limit. The SVG+FC compensation device is used to compensate, which will lead to the SVG capacity greatly reduced, and the cost and investment of the project are reduced to the greatest extent. Moreover, the fast operation speed of SVG can effectively solve the problems of harmonic filtering and reactive power compensation, which can meet the requirements of all aspects of real-time compensation. After compensation, the power quality of the common point is significantly improved, and the economy and operation flexibility of the compensation device are good.